CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net income	$ 15,130	$ 7,151
Adjustments to reconcile net income to net cash and cash equivalents provided by operating activities:
Amortization of intangibles	380	505
Depreciation	1,310	924
Foreign currency exchange loss	183	269
Change in fair value of contingent consideration	318	132
Share-based compensation	1,507	1,148
Provision for doubtful accounts and inventory valuation	705	951
Changes in operating assets and liabilities	(14,894)	3,144
Net cash and cash equivalents provided by operating activities	4,639	14,224
Cash flows from investing activities:
Purchases of marketable securities	(57,134)	(22,449)
Proceeds from sales of marketable securities	54,404	25,355
Purchases of property, plant and equipment	(1,442)	(1,724)
Net cash and cash equivalents (used in) provided by investing activities	(4,172)	1,182
Cash flows from financing activities:
Redemption of stock warrants	0	(1,025)
Tax payments related to shares withheld for share-based compensation plans	(839)	(803)
Issuance of shares through share-based compensation plans	122	107
Net cash and cash equivalents used in financing activities	(717)	(1,721)
Effect of exchange rate changes on cash and cash equivalents	535	701
Net increase in cash and cash equivalents	285	14,386
Cash and cash equivalents at beginning of period	67,770	37,859
Cash and cash equivalents at end of period	68,055	52,245
Supplemental disclosure of cash flow information:
Income taxes paid	$ 249	$ 208